1. Field of the Invention
The present invention relates to a database system, a data management system and a communication terminal which are for use in an information providing service system using a communication system such as a radio paging system.
2. Description of the Prior Art
A radio paging system and a home banking system are available as communication systems which transmit/receive character information through conventional telephone lines.
In particular, as regards the radio paging system among those communication systems, the standard "RCR STD-43" has been brought into practice.
The "RCR STD-43" will now be briefly described. FIG. 58 shows the data structure according to the "RCR STD-43". In FIG. 58, reference numeral 101 represents the structure of data transmitted in one hour.
Reference numeral 102 denotes the structure of 1-cycle data (hereinafter referred to as the cycle structure). Reference numeral 103 represents the structure of 1-frame data (hereinafter referred to as the frame structure). The data structure 101 includes 15-cycle data which consists of data items numbered "0" to "14", and those data items are transmitted in one hour. The cycle structure 102 includes 128 frames numbered "0" to 127", and those frames are transmitted in four minutes. The time required to transmit 1 frame is 1.875 sec., and 32 frames are transmitted per minute. The frame structure 103 shows the structure of 1-frame data, which is divided into eight in accordance with the contents of the 1-frame data.
The frame structure 103 is made up of a synchronization 1 (S1) 103A, frame information (FI) 103B, a synchronization 2 (S2) 103C, block information section (BI) 103D, an address field (AF) 103E, a vector field (VF) 103F, a message field (MF) 103G and idle blocks (IB) 103H.
The synchronization 1 (S1) 103A consists of 112 bits which have been subjected to binary FSK modulation and which are transmitted at a speed of 1600 bps. The synchronization 1 (S1) 103A stores information specifying which of the following the data modulation method or transmission speed of data transmitted by the block information section (BI) 103D and the subsequent fields and block is:
Binary FSK Modulation/1600 bps PA1 Binary FSK Modulation/3200 bps PA1 Quadrature FSK Modulation/3200 bps PA1 Quadrature Modulation/6400 bps PA1 the management means comprising PA1 detection means for detecting storage times at which the above-mentioned data items have been stored in the database, PA1 means for causing the database to store the storage times detected by the detection means, in association with the pieces of ID information, and PA1 first transmission control means for controlling the transmission means so as to transmit, of the storage times stored in the database, one storage time corresponding to the aforementioned one piece of ID information to the at least one communication terminal, together with that piece of ID information. PA1 size detection means for detecting the sizes of the data items stored in the database, and PA1 second transmission control means for controlling the transmission means so as to transmit, of the sizes detected by the size detection means, one size corresponding to the aforementioned one piece of ID information to the at least one communication terminal, together with that piece of ID information. PA1 size detection means for detecting the sizes of the data items stored in the database, and PA1 second transmission control means for controlling the transmission means so as to transmit, of the sizes detected by the size detection means, one size corresponding to the aforementioned one piece of ID information to the at least one communication terminal, together with that piece of ID information; and PA1 the at least one communication terminal may further comprise PA1 means for causing the database to store pieces of attribute information specifying the attributes of the data items, in association with the pieces of ID information, and PA1 third transmission control means for controlling the transmission means so as to transmit, of the pieces of attribute information, one piece of attribute information corresponding to the aforementioned one piece of ID information; and the at least one communication terminal may further comprise PA1 display means for displaying information, PA1 fifth storage means for storing pieces of display control information in association with pieces of ID information which are substantially same as the pieces of information stored in the database, and PA1 display control means for reading out, of the pieces of display control information stored in the fifth storage means, one piece of display control information corresponding to the piece of ID information received by the reception means, and for controlling the display means. PA1 alert means for alerting the user of the communication terminal when the reception means receives the aforementioned one piece of ID information, PA1 sixth storage means for storing pieces of alert control information in association with pieces of ID information which are substantially same as the pieces of information stored in the database, and PA1 alert control means for reading out, of the pieces of alert control information stored in the sixth storage means, one piece of alert control information corresponding to the piece of ID information received by the reception means, and for controlling the alert means. PA1 the data management system comprising PA1 detection means for detecting storage times at which the data items have been stored in the database, PA1 means for causing the database to store the storage times detected by the detection means, in association with the pieces of ID information, and PA1 first transmission control means for controlling the transmission means so as to transmit, of the storage times stored in the database, one storage time corresponding to the aforementioned one piece of ID information to the at least one terminal, together with that piece of ID information. PA1 size detection means for detecting the sizes of the data items stored in the database, and PA1 second transmission control means for controlling the transmission means so as to transmit, of the sizes detected by the size detection means, one size corresponding to the aforementioned one piece of ID information to the at least one terminal, together with that piece of ID information. PA1 third control means for controlling the transmission means so as to transmit the aforementioned one piece of ID information simultaneously to a group which consists of the at least one terminal. PA1 the communication terminal comprising PA1 first storage means for storing the data item extracted from the database by the extraction means. PA1 measurement means for measuring the remaining capacity of the first storage means, PA1 detection means for detecting the size of a desired data item identified by one of the pieces of ID information received by the reception means, PA1 comparison means for comparing the size detected by the detection means with the remaining capacity measured by the measurement means, and PA1 first inhibition means for inhibiting the extraction means from extracting the data item when the size is greater than the remaining capacity as a result of the comparison performed by the comparison means. PA1 second storage means for storing a data processing program together with the attributes of data which can be processed using the data processing program, PA1 third storage means for storing pieces of attribute information in association with the pieces of ID information, each of the pieces of attribute information specifying an attribute of one of the data items identified by the pieces of ID information, PA1 determination means for reading out, from the third storage means, one of the pieces of attribute information received by the reception means, and for determining whether the data item corresponding to the aforementioned one piece of attribute information can be processed using the program stored in the second storage means, and PA1 second inhibition means for inhibiting the extraction means from extracting the data item when the determination means determines that the data item corresponding to the aforementioned one piece of attribute information cannot be processed using the data processing program stored in the second storage means. PA1 fourth storage means for storing, in association with the pieces of ID information, pieces of reception control information for controlling the reception means. PA1 display means for displaying information, PA1 fifth storage means for storing pieces of display control information in association with pieces of ID information which are substantially same as the pieces of information received by the reception means, and PA1 display control means for reading out the pieces of display control information from the fifth storage means in accordance with the pieces of ID information received by the reception means, and for controlling the display means. PA1 alert means for alerting the user of the at least one communication terminal when the reception means receives the pieces of ID information, PA1 sixth storage means for storing pieces of alert control information in association with pieces of ID information which are substantially same as the pieces of information received by the reception means, and PA1 alert control means for reading out the pieces of alert control information from the sixth storage means in accordance with the pieces of ID information received by the reception means, and for controlling the alert means. PA1 seventh storage means for storing, in association with each other, the pieces of ID information and pieces of link information to establish links with the database. PA1 a transmitting step of transmitting pieces of ID information, identifying data items stored in the database, to the at least one terminal through the communication line network; PA1 a receiving step of receiving the pieces of ID information transmitted in the transmitting step; PA1 a selecting step of selecting one of the pieces of ID information received in the receiving step; PA1 an accessing step of accessing the database in accordance with the selected piece of ID information selected in he selecting step; and PA1 a data obtaining step of accessing the database in accordance with the selected piece of ID information selected in the selecting step and obtaining the data item identified by the selected piece of ID information from the database; PA1 wherein the receiving step, the accessing step and the obtaining step are performed on the part of the at least one terminal.
The frame information (FI) 103B consists of a 32-bit word subjected to the binary FSK modulation and whose bits are transmitted at a speed of 1600 bps. The frame information (FI) 103B stores frame numbers, cycle numbers, information specifying the number of transmission times. The synchronization 2 (S2) 103C stores timing information for realizing the transmission timing according to the modulation method and transmission speed specified in the synchronization 1 (S1) 103A.
The information stored in the block information (BI) 103D to the idle blocks (IB) 103H is modulated by the modulation method specified in the synchronization 1 (S1) 103A, and is transmitted at the speed specified in the synchronization 1 (S1) 103A. The information stored in the block information (BI) 103D to the idle blocks (IB) 103H consists of eleven blocks each being transferred in 160 ms. The block information (BI) 103D stores information such as the number of words, the word numbers representing the starting points of the address field (AF) 103E and vector field (VF) 103F, etc., as will be described later. The address field (AF) 103E stores address data indicating the pager (or pagers) to be paged. The vector field (VF) 103F stores the number of words, the word number representing the starting point of the message field (MF) 103G, etc., as will be described later. The message field (MF) 103G stores message data according to the data format specified in the vector field (VF) 103F. The idle blocks (BI) 103H is an unused block, in which the pattern "1" or "0" is set.
Using the "RCR STD-43", a central paging controller which performs a paging service can also carry out the information providing service of supplying information messages having various service contents simultaneously to the pagers owned by a larger number of subscribers, in addition to an individual subscriber paging service.
If the subscribers desire to enjoy the "information providing service", their pagers (hereinafter referred to as the pagers of the users) can receive the information messages of various service contents which are supplied from an information providing company.
According to the "RCR STD-43", a large amount of data. can be transmitted at a time to the pagers of the users. However, in the case of the "RCR STD-43", the format prescribed thereby is a short sentence, and the amount of data which can be transmitted is limited.
The contents of the information providing service utilizing the paging system are also various and range from business information to local information connected with the area in which the information providing service is available. Accordingly, the users' needs for the information to be provided are changing from those for information like an exchange rate, which can be expressed using a set format, toward those for information like one concerning concert tickets and the sales/purchase of objects among the individual users.
In order to satisfy the users' needs, the information providing company (service center) is making an attempt to provide information which is difficult to express using the prescribed format. Basically, however, the pagers which accord with the "RCR STD-43" can receive only data having the format prescribed thereby. Since the capacities of their internal memories are limited, the pagers cannot receive a large amount of data of other formats at a time.
Meanwhile, a method is known wherein a cellular phone and a notebook-type personal computer are connected to each other through utilization of a personal communication service (PCS) system, thus allowing data files having various formats, such as an image, an electronic mail, etc., to be exchanged between the cellular phone and the personal computer, and enabling a desired data file to be downloaded from a database of the company in which a user is employed. According to the above method, however, in the case where the user, for example, downloads information stored in the database to the notebook-type personal computer after a line connection has been established between the cellular phone and the database, the user cannot discriminate which is the data file to be downloaded unless he/she searches the database.